I love it how this position has been neglected since the 19th century...

Yes indeed . I have ten games with 6 Nc3 from 1865-1894 and then... nothing... until my own games 2006-2017.

On the theory, I've always played 6...Kd8 but have found the line 7 Nxe4 c6 8 Nf3 Qe7 9 Neg5 to be far more difficult to defend than it looks. Yes, maybe 11...Qxe2+ makes more sense than 11...Bg4 in the game under discussion. If Black is going to play this anyway, it makes sense to do so straight away.

If we look for earlier ideas, there are several in move six. I love it how this position has been neglected since the 19th century... Perhaps best is 6...Be7! =, while 6...Nc6 and 6...Ne7 are also worth a look.

Move three ... but let's not go there, it would be dangerously close to the Wagenbach swamp.

It's always a question that plagues me in such endings: how would I fare over the board? Hard to play precisely, although targeting the d-pawn must be the key. The PC offers 30...Kb6 as an alternative. It's attractive for humans, as in some lines the King can play an active role: Ka5-b4. The main line is 31.Rb2+ Kc7 32.Rf7+ Kd6 33.Rbb7 Rd3+ 34.Kc2 Rxd4 35.Kc3 Rh4 36.Rxh7 Rxh7 37.Rxh7 Ra8, +0.69. This should be a draw.

Books argue 4-rook endings offer more practical chances for the defender than exchanging a pair of rooks. Easy to play they are not.

Well, okay, then. 27...Rd8 and draws.

All the same, for the theory of 3...f5, I'm not sure whether it's practical for me to base it on a difficult double rook endgame for Black. Any suggestions earlier on?

It's always a question that plagues me in such endings: how would I fare over the board? Hard to play precisely, although targeting the d-pawn must be the key. The PC offers 30...Kb6 as an alternative. It's attractive for humans, as in some lines the King can play an active role: Ka5-b4. The main line is 31.Rb2+ Kc7 32.Rf7+ Kd6 33.Rbb7 Rd3+ 34.Kc2 Rxd4 35.Kc3 Rh4 36.Rxh7 Rxh7 37.Rxh7 Ra8, +0.69. This should be a draw.

Books argue 4-rook endings offer more practical chances for the defender than exchanging a pair of rooks. Easy to play they are not.

Re 29...Ke7 – maybe I didn't look at that as closely as I should, since I was deliberately aiming for the endgame in the main line. But in general I thought Black had more chances with the h-pawn than the f-pawn. For instance, after something like 30 Rh6 f3 31 Rxh5 Rf8 32 Re5+ Kf6 33 Rdd5 Rh8 34 Rf5+ Ke6 35 Kc2 Rhh2 36 Rf4 Rf1 37 Rd3 f2 38 Rdf3, I'm not sure whether it's possible just to sit on this, as White can make progress with Kd4, d2-d3, edging slowly forwards, and getting the a-pawn for the f-pawn isn't enough for Black here. Those endgames seem always to be lost.

I just did a quick pass through the moves. After 53.Rb6+, 53...Ke5 seems wrong. Instead 53...Ke7 54.Rxa6 Kd8 and for the moment white cannot trade rooks, later black might draw even without the h-pawn.

Re 53...Ke7 – no, it makes no difference at that point where the king goes, since 54 Rxa6 is a winning endgame according to Lomonosov. Apparently after 55...Kd8, it's mate in 30! But otherwise, yes, a drawn R+a+c v R is what I was playing for in a lot of cases. I just missed that with 52 d7! he could force one that is winning for White.

Re 29...Ke7 – maybe I didn't look at that as closely as I should, since I was deliberately aiming for the endgame in the main line. But in general I thought Black had more chances with the h-pawn than the f-pawn. For instance, after something like 30 Rh6 f3 31 Rxh5 Rf8 32 Re5+ Kf6 33 Rdd5 Rh8 34 Rf5+ Ke6 35 Kc2 Rhh2 36 Rf4 Rf1 37 Rd3 f2 38 Rdf3, I'm not sure whether it's possible just to sit on this, as White can make progress with Kd4, d2-d3, edging slowly forwards, and getting the a-pawn for the f-pawn isn't enough for Black here. Those endgames seem always to be lost.

I just did a quick pass through the moves. After 53.Rb6+, 53...Ke5 seems wrong. Instead 53...Ke7 54.Rxa6 Kd8 and for the moment white cannot trade rooks, later black might draw even without the h-pawn.